The creatures of Asengervald are, for the most part, familiar to Dungeons and Dragons aficionados. They might not have exactly the same name or follow quite the same rules as their 3.5 counterparts, but the goal is to keep them familiar enough that you get to fight familiar enemies, but different enough that they’re a bit surprising.
The most common “monsters” are animals and vermin, as with most real-word ecologies, but the exact varieties depart quite a bit from “normal” ecology. Dire versions of animals are very common and, at least in the Weftsjot, are the default animal type. This is partly because of the harsh nature of the landscape, but also because Asengervald is a primeval place.
There are dragons of course, from small (or at least smallish) drakes to gigantic chromatic and metallic dragons. As with some D & D settings, you can’t always count on knowing a dragon’s attitude towards people just by determining what type it is. Most dragons are greedy creatures interested in their own gain more than anything, but a few have other interests. What these are are one of the deeper mysteries of Asengervald.
Humans are generally considered the dominant race, but there are dwarves, athaminar and gnomes as well. Any halflings are visitors from other lands. Half-orcs are reasonably common as well, but are only found in orc communities.